package com.gitee.sop.layui.adminserver.frameword.init.constants;

import com.gitee.sop.layui.adminserver.frameword.init.listener.SystemPropertiesListener;

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * 系统常量
 *
 * @author: huwei
 * @date: 2019/10/18 15:22
 * @version: 1.0.0
 */
public class SystemConstant {
    /**
     * 系统根包
     */
    public static final String ROOT_PACKAGE = "com.wlx.visting";
    /**
     * 常量容器
     */
    private static final Map<String, String> CONSTANT = new ConcurrentHashMap<>(16);

    /**
     * 被当前类信任的对象 ,只有被当前对象信任才能调用put方法 ，该限定，是为了防止在系统运行中常量被动态修改
     */
    private static final Map<String, Class<?>> BY_TRUST_CLASS = new ConcurrentHashMap<>(1);

    static {
        BY_TRUST_CLASS.put(SystemPropertiesListener.class.getName(), SystemPropertiesListener.class);
    }

    public static String get(String key) {
        return CONSTANT.get(key);
    }

    public static String get(String key, String def) {
        String res = CONSTANT.get(key);
        return res == null ? def : res;
    }

    public static void put(String key, String val) {
        checkTrust();
        CONSTANT.put(key, val);
    }

    public static void putAll(Map<String, String> maps) {
        checkTrust();
        CONSTANT.putAll(maps);
    }

    private static void checkTrust() {
        if (!isTrustClass()) {
            throw new RuntimeException("初始化常量只能在系统启动时修改，或被信任的类对象修改.");
        }
    }

    private static boolean isTrustClass() {
        StackTraceElement[] stack = (new Throwable()).getStackTrace();
        for (StackTraceElement stackTraceElement : stack) {
            if (BY_TRUST_CLASS.get(stackTraceElement.getClassName()) != null) {
                return true;
            }
        }
        return false;
    }

    public static void println() {
        System.err.println(CONSTANT);
    }

    public static String systemName() {
        return get("system-name");
    }

    public static String contextPath() {
        String contextPath = get("context-path");
        if (contextPath == null) {
            contextPath = get("context-path2");
        }
        return contextPath;
    }

    public static String systemPort() {
        return get("system-port");
    }

    public static String applicationName() {
        return get("application-name");
    }
}
